Is there any indication that increasing the use of“clanker” makes society more racist? One could argue by finally making the target of a racist-style slur a robot is actually uniting humanity together against a common enemy.

Will racist appropriate it like they do everything else? Probably, but if that use isn't semantically dominant, there isn't a real problem.

Second, there is a tendency to view hatred negatively. Whether you like it or not, there is a permanent population looking to hate something. If you don't give them something to hate, your enemies will--and it will likely be you.